With the development of the information technology and great demands of people for communication bandwidths, the communication network has changed from the analog network to the digital network, the development of the optic fiber technology has greatly promoted the development of the digital communication technology and met the demands of people for the communication bandwidths. The optical fiber communication which provides low cost, high speed information services, has replaced the conventional copper cable communication rapidly. To adapt to the development of the optical fiber technology, unify products of various communication manufacturers, and achieve the transmission information intercommunication, the International Telecommunication Union has made an SDH communication standard. The frame information structure of the SDH hierarchy has rich overhead bytes, which facilitates information transmission and network management, unified interface parameters can make the equipments of different manufacturers perform networking jointly, which achieves the intercommunication between the communication networks over regions even over the world, thereby these advantages make the transmission networks based on SDH become a dominant direction for building optical communication networks. However new networks are built on the basis of original networks, new SDH networks need to be compatible with previous PDH structure networks, meet the transmission of information from the SDH architecture to the PHD architecture, and achieve that the communication information can be transmitted between different communication network structures. When an SDH network co-exists with a PDH network, a low-speed signal needs to be transmitted through the SDH hierarchy, the simple multiplexing way from the low-speed signal to the high-speed signal in the PDH hierarchy is not applied any more. When signals such as E1, T1, etc., are transmitted in the SDH frame structure, it is necessary to adopt stuffed adjustment bits and fixed stuffing bits, add path overhead bits to the signals, and the signals are multiplexed to the SDH frame structure; similarly when the signals are recovered from SDH frame structure to PDH structure, it is necessary to solve virtual container signals, remove the overhead bits, fixed stuffing bits and adjustment bits, and the E1, T1 signals are recovered. The recovery circuit is a key circuit to achieve the transmission of the signals from the SDH frame structure to the PDH structure, which relates to synchronization information and a jitter index of a clock when the signals pass through different hierarchies. There are 84 T1 tributary signals or 63 E1 tributary signals included in the STM-1 frame structure, because the tributary signals are independent on each other, clocks in different tributaries are different, generally in implementation, recovery is performed separately for each tributary, for example, in china patent CN1638283: Single crystal vibrator digital phase-locked loop device realizing E1 T1 de-jittering. The clock recovery of the single tributary signal is achieved in that patent, but for STM-1 frame, there are 63 E1 tributary signals, when that patent is applied, 63 separate circuit recovery clocks are needed. Compared to the single E1 signal, 63 E1 tributary signals need 63 clock recovery circuits, and 63 times clock resources are consumed. There are 84 T1 tributary signals in STM-1 frame, when that patent is applied, 84 separate recovery circuits are needed. For STM-16, there are 1008 E1 tributary signals, which need to consume 1008 resources, and resource consumption is very large.